gdb/tm-rs6000.h

   1 /* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
   2    Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
   3    Contributed by IBM Corporation.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21
  22 /* A successful ptrace(continue) might return errno != 0 in this particular port
  23    of rs6000. I am not sure why. We will use this kludge and ignore it until
  24    we figure out the real problem. */
  25
  26 #define AIX_BUGGY_PTRACE_CONTINUE       \
  27 { \
  28   int ret = ptrace (PT_CONTINUE, inferior_pid, (int *)1, signal, 0); \
  29   if (errno) { \
  30 /*    printf ("ret: %d, errno: %d, signal: %d\n", ret, errno, signal); */ \
  31     errno = 0; } \
  32 }
  33
  34 extern int      symtab_relocated;
  35
  36 /* Minimum possible text address in AIX */
  37
  38 #define TEXT_SEGMENT_BASE       0x10000000
  39
  40
  41 /* text addresses in a core file does not necessarily match to symbol table,
  42    if symbol table relocation wasn't done yet. */
  43
  44 #define CORE_NEEDS_RELOCATION(PC)       \
  45   if (!symtab_relocated && !inferior_pid && (PC) >  TEXT_SEGMENT_BASE)  \
  46     (PC) -= ( TEXT_SEGMENT_BASE + text_adjustment (exec_bfd));
  47
  48 /* Load segment of a given pc value. */
  49
  50 #define PC_LOAD_SEGMENT(PC)     pc_load_segment_name(PC)
  51
  52
  53 /* Conversion between a register number in stab string to actual register num. */
  54
  55 #define STAB_REG_TO_REGNUM(value)       (value)
  56
  57 /* return true if a given `pc' value is in `call dummy' function. */
  58
  59 #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR)     \
  60         (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
  61
  62 /* For each symtab, we keep track of which BFD it came from.  */
  63 #define EXTRA_SYMTAB_INFO       \
  64         unsigned    nonreloc:1;         /* TRUE if non relocatable */
  65
  66 #define INIT_EXTRA_SYMTAB_INFO(symtab)  \
  67         symtab->nonreloc = 0;           \
  68
  69 extern unsigned int text_start, data_start;
  70 extern int inferior_pid;
  71 extern char *corefile;
  72
  73 /* setpgrp() messes up controling terminal. The other version of it
  74    requires libbsd.a. */
  75 #define setpgrp(XX,YY)          setpgid (XX, YY)
  76
  77 /* We are missing register descriptions in the system header files. Sigh! */
  78
  79 struct regs {
  80         int     gregs [32];             /* general purpose registers */
  81         int     pc;                     /* program conter       */
  82         int     ps;                     /* processor status, or machine state */
  83 };
  84
  85 struct fp_status {
  86         double  fpregs [32];            /* floating GP registers */
  87 };
  88
  89
  90 /* To be used by function_frame_info. */
  91
  92 struct aix_framedata {
  93   int   offset;                         /* # of bytes in gpr's and fpr's are saved */
  94   int   saved_gpr;                      /* smallest # of saved gpr */
  95   int   saved_fpr;                      /* smallest # of saved fpr */
  96   int   alloca_reg;                     /* alloca register number (frame ptr) */
  97   char  frameless;                      /* true if frameless functions. */
  98 };
  99
 100
 101 /* Define the byte order of the machine.  */
 102
 103 #define TARGET_BYTE_ORDER       BIG_ENDIAN
 104
 105 /* Define this if the C compiler puts an underscore at the front
 106    of external names before giving them to the linker.  */
 107
 108 #undef NAMES_HAVE_UNDERSCORE
 109
 110 /* AIX's assembler doesn't grok dollar signs in identifiers.
 111    So we use dots instead.  This item must be coordinated with G++. */
 112 #undef CPLUS_MARKER
 113 #define CPLUS_MARKER '.'
 114
 115 /* Offset from address of function to start of its code.
 116    Zero on most machines.  */
 117
 118 #define FUNCTION_START_OFFSET 0
 119
 120 /* Advance PC across any function entry prologue instructions
 121    to reach some "real" code.  */
 122
 123 #define SKIP_PROLOGUE(pc)       pc = skip_prologue (pc)
 124
 125 /* If PC is in some function-call trampoline code, return the PC
 126    where the function itself actually starts.  If not, return NULL.  */
 127
 128 #define SKIP_TRAMPOLINE_CODE(pc)        skip_trampoline_code (pc)
 129
 130 /* When a child process is just starting, we sneak in and relocate
 131    the symbol table (and other stuff) after the dynamic linker has
 132    figured out where they go. But we want to do this relocation just
 133    once. */
 134
 135 extern int aix_loadInfoTextIndex;
 136
 137 #define SOLIB_CREATE_INFERIOR_HOOK(PID) \
 138   do {                                  \
 139     if (aix_loadInfoTextIndex == 0)     \
 140         aixcoff_relocate_symtab (PID);  \
 141   } while (0)
 142
 143
 144 /* Number of trap signals we need to skip over, once the inferior process
 145    starts running. */
 146
 147 #define START_INFERIOR_TRAPS_EXPECTED   2
 148
 149 /* AIX might return a sigtrap, with a "stop after load" status. It should
 150    be ignored by gdb, shouldn't be mixed up with breakpoint traps. */
 151
 152 /* Another little glitch  in AIX is signal 0. I have no idea why wait(2)
 153    returns with this status word. It looks harmless. */
 154
 155 #define SIGTRAP_STOP_AFTER_LOAD(W)      \
 156  if ( (W) == 0x57c || (W) == 0x7f) {    \
 157    if ((W)==0x57c && breakpoints_inserted) {    \
 158      mark_breakpoints_out ();           \
 159      insert_breakpoints ();             \
 160      insert_step_breakpoint ();         \
 161    }                                    \
 162    resume (0, 0);                       \
 163    continue;                            \
 164  }
 165
 166 /* In aixcoff, we cannot process line numbers when we see them. This is
 167    mainly because we don't know the boundaries of the include files. So,
 168    we postpone that, and then enter and sort(?) the whole line table at
 169    once, when we are closing the current symbol table in end_symtab(). */
 170
 171 #define PROCESS_LINENUMBER_HOOK()       aix_process_linenos ()
 172
 173
 174 /* When a target process or core-file has been attached, we sneak in
 175    and figure out where the shared libraries have got to. In case there
 176    is no inferior_process exists (e.g. bringing up a core file), we can't
 177    attemtp to relocate symbol table, since we don't have information about
 178    load segments. */
 179
 180 #define SOLIB_ADD(a, b, c)      \
 181    if (inferior_pid)    aixcoff_relocate_symtab (inferior_pid)
 182
 183 /* Immediately after a function call, return the saved pc.
 184    Can't go through the frames for this because on some machines
 185    the new frame is not set up until the new function executes
 186    some instructions.  */
 187
 188 #define SAVED_PC_AFTER_CALL(frame)      \
 189         (register_valid [LR_REGNUM] ?   \
 190           (*(int*)&registers[REGISTER_BYTE (LR_REGNUM)]) :      \
 191           read_register (LR_REGNUM))
 192
 193 /*#define SAVED_PC_AFTER_CALL(frame)    saved_pc_after_call(frame) */
 194
 195
 196 /* Address of end of stack space.  */
 197
 198 #define STACK_END_ADDR 0x2ff80000
 199
 200 /* Stack grows downward.  */
 201
 202 #define INNER_THAN <
 203
 204 #if 0
 205 /* No, we shouldn't use this. push_arguments() should leave stack in a
 206    proper alignment! */
 207 /* Stack has strict alignment. */
 208
 209 #define STACK_ALIGN(ADDR)       (((ADDR)+7)&-8)
 210 #endif
 211
 212 /* This is how argumets pushed onto stack or passed in registers. */
 213
 214 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
 215   sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
 216
 217 /* Sequence of bytes for breakpoint instruction.  */
 218
 219 #define BREAKPOINT {0x7d, 0x82, 0x10, 0x08}
 220
 221 /* Amount PC must be decremented by after a breakpoint.
 222    This is often the number of bytes in BREAKPOINT
 223    but not always.  */
 224
 225 #define DECR_PC_AFTER_BREAK 0
 226
 227 /* Nonzero if instruction at PC is a return instruction.  */
 228 /* Allow any of the return instructions, including a trapv and a return
 229    from interrupt.  */
 230
 231 #define ABOUT_TO_RETURN(pc)  \
 232    ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
 233
 234 /* Return 1 if P points to an invalid floating point value.  */
 235
 236 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
 237
 238 /* Largest integer type */
 239
 240 #define LONGEST long
 241
 242 /* Name of the builtin type for the LONGEST type above. */
 243
 244 #define BUILTIN_TYPE_LONGEST builtin_type_long
 245
 246 /* Say how long (ordinary) registers are.  */
 247
 248 #define REGISTER_TYPE long
 249
 250 /* Number of machine registers */
 251
 252 #define NUM_REGS 71
 253
 254 /* Initializer for an array of names of registers.
 255    There should be NUM_REGS strings in this initializer.  */
 256
 257 #define REGISTER_NAMES  \
 258  {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",  \
 259   "r8", "r9", "r10","r11","r12","r13","r14","r15", \
 260   "r16","r17","r18","r19","r20","r21","r22","r23", \
 261   "r24","r25","r26","r27","r28","r29","r30","r31", \
 262   "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",  \
 263   "f8", "f9", "f10","f11","f12","f13","f14","f15", \
 264   "f16","f17","f18","f19","f20","f21","f22","f23", \
 265   "f24","f25","f26","f27","f28","f29","f30","f31", \
 266   "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
 267
 268 /* Register numbers of various important registers.
 269    Note that some of these values are "real" register numbers,
 270    and correspond to the general registers of the machine,
 271    and some are "phony" register numbers which are too large
 272    to be actual register numbers as far as the user is concerned
 273    but do serve to get the desired values when passed to read_register.  */
 274
 275 #define FP_REGNUM 1             /* Contains address of executing stack frame */
 276 #define SP_REGNUM 1             /* Contains address of top of stack */
 277 #define TOC_REGNUM 2            /* TOC register */
 278 #define FP0_REGNUM 32           /* Floating point register 0 */
 279 #define GP0_REGNUM 0            /* GPR register 0 */
 280 #define FP0_REGNUM 32           /* FPR (Floating point) register 0 */
 281 #define FPLAST_REGNUM 63        /* Last floating point register */
 282
 283 /* Special purpose registers... */
 284 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
 285    easier processing */
 286
 287 #define PC_REGNUM 64            /* Program counter (instruction address %iar) */
 288 #define PS_REGNUM 65            /* Processor (or machine) status (%msr) */
 289 #define CR_REGNUM 66            /* Condition register */
 290 #define LR_REGNUM 67            /* Link register */
 291 #define CTR_REGNUM 68           /* Count register */
 292 #define XER_REGNUM 69           /* Fixed point exception registers */
 293 #define MQ_REGNUM 70            /* Multiply/quotient register */
 294
 295 #define FIRST_SP_REGNUM 64      /* first special register number */
 296 #define LAST_SP_REGNUM  70      /* last special register number */
 297
 298 /* Total amount of space needed to store our copies of the machine's
 299    register state, the array `registers'.
 300
 301         32 4-byte gpr's
 302         32 8-byte fpr's
 303         7  4-byte special purpose registers,
 304
 305    total 416 bytes. Keep some extra space for now, in case to add more. */
 306
 307 #define REGISTER_BYTES 420
 308
 309
 310 /* Index within `registers' of the first byte of the space for
 311    register N.  */
 312
 313 #define REGISTER_BYTE(N)  \
 314  (                                                              \
 315   ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
 316   :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128)       \
 317   :((N) * 4) )
 318
 319 /* Number of bytes of storage in the actual machine representation
 320    for register N. */
 321 /* Note that the unsigned cast here forces the result of the
 322    subtractiion to very high positive values if N < FP0_REGNUM */
 323
 324 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 325
 326 /* Number of bytes of storage in the program's representation
 327    for register N.  On the RS6000, all regs are 4 bytes
 328    except the floating point regs which are 8-byte doubles.  */
 329
 330 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 331
 332 /* Largest value REGISTER_RAW_SIZE can have.  */
 333
 334 #define MAX_REGISTER_RAW_SIZE 8
 335
 336 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 337
 338 #define MAX_REGISTER_VIRTUAL_SIZE 8
 339
 340 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
 341
 342 #define STAB_REG_TO_REGNUM(value)       (value)
 343
 344 /* Nonzero if register N requires conversion
 345    from raw format to virtual format.  */
 346
 347 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
 348
 349 /* Convert data from raw format for register REGNUM
 350    to virtual format for register REGNUM.  */
 351
 352 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 353    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 354
 355 /* Convert data from virtual format for register REGNUM
 356    to raw format for register REGNUM.  */
 357
 358 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 359    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 360
 361 /* Return the GDB type object for the "standard" data type
 362    of data in register N.  */
 363
 364 #define REGISTER_VIRTUAL_TYPE(N) \
 365  (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
 366
 367 /* Store the address of the place in which to copy the structure the
 368    subroutine will return.  This is called from call_function. */
 369 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
 370    In function return, callee is not responsible of returning this address back.
 371    Since gdb needs to find it, we will store in a designated variable
 372    `rs6000_struct_return_address'. */
 373
 374 extern unsigned int rs6000_struct_return_address;
 375
 376 #define STORE_STRUCT_RETURN(ADDR, SP)   \
 377   { write_register (3, (ADDR));         \
 378     rs6000_struct_return_address = (unsigned int)(ADDR); }
 379
 380 /* Extract from an array REGBUF containing the (raw) register state
 381    a function return value of type TYPE, and copy that, in virtual format,
 382    into VALBUF.  */
 383
 384 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 385   bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE)) */
 386
 387 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 388   extract_return_value(TYPE,REGBUF,VALBUF)
 389
 390 /* Write into appropriate registers a function return value
 391    of type TYPE, given in virtual format.  */
 392
 393 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 394   {                                                                     \
 395     if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)                              \
 396                                                                         \
 397      /* Floating point values are returned starting from FPR1 and up.   \
 398         Say a double_double_double type could be returned in            \
 399         FPR1/FPR2/FPR3 triple. */                                       \
 400                                                                         \
 401       write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF),     \
 402                                                 TYPE_LENGTH (TYPE));    \
 403     else                                                                \
 404       /* Everything else is returned in GPR3 and up. */                 \
 405       write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF),     \
 406                                                 TYPE_LENGTH (TYPE));    \
 407   }
 408
 409
 410 /* Extract from an array REGBUF containing the (raw) register state
 411    the address in which a function should return its structure value,
 412    as a CORE_ADDR (or an expression that can be used as one).  */
 413
 414 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF)    rs6000_struct_return_address
 415
 416
 417 /* Do implement the attach and detach commands.  */
 418
 419 #define ATTACH_DETACH
 420
 421 /* infptrace.c requires those. */
 422
 423 #define PTRACE_ATTACH 30
 424 #define PTRACE_DETACH 31
 425
 426 \f
 427 /* Describe the pointer in each stack frame to the previous stack frame
 428    (its caller).  */
 429
 430 /* FRAME_CHAIN takes a frame's nominal address
 431    and produces the frame's chain-pointer. */
 432
 433 /* In the case of the RS6000, the frame's nominal address
 434    is the address of a 4-byte word containing the calling frame's address.  */
 435
 436 #define FRAME_CHAIN(thisframe)  \
 437   (!inside_entry_file ((thisframe)->pc) ?       \
 438    read_memory_integer ((thisframe)->frame, 4) :\
 439    0)
 440
 441 /* Define other aspects of the stack frame.  */
 442
 443 /* A macro that tells us whether the function invocation represented
 444    by FI does not have a frame on the stack associated with it.  If it
 445    does not, FRAMELESS is set to 1, else 0.  */
 446
 447 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 448         FRAMELESS = frameless_function_invocation (FI)
 449
 450 /* Functions calling alloca() change the value of the stack pointer. We
 451    need to use initial stack pointer (which is saved in r31 by gcc) in
 452    such cases. If a compiler emits traceback table, then we should use the
 453    alloca register specified in traceback table. FIXME. */
 454 /* Also, it is a good idea to cache information about frame's saved registers
 455    in the frame structure to speed things up. See tm-m88k.h. FIXME. */
 456
 457 #define EXTRA_FRAME_INFO        \
 458         CORE_ADDR initial_sp;                   /* initial stack pointer. */ \
 459         struct frame_saved_regs *cache_fsr;     /* saved registers        */
 460
 461 /* Frameless function invocation in IBM RS/6000 is half-done. It perfectly
 462    sets up a new frame, e.g. a new frame (in fact stack) pointer, etc, but it
 463    doesn't save the %pc. In the following, even though it is considered a
 464    frameless invocation, we still need to walk one frame up. */
 465
 466 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi)     \
 467         fi->initial_sp = 0;             \
 468         fi->cache_fsr = 0;
 469
 470 #define FRAME_SAVED_PC(FRAME)           \
 471         read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4)
 472
 473 #define FRAME_ARGS_ADDRESS(FI)  \
 474   (((struct frame_info*)(FI))->initial_sp ?             \
 475         ((struct frame_info*)(FI))->initial_sp :        \
 476         frame_initial_stack_address (FI))
 477
 478 #define FRAME_LOCALS_ADDRESS(FI)        FRAME_ARGS_ADDRESS(FI)
 479
 480
 481 /* Set VAL to the number of args passed to frame described by FI.
 482    Can set VAL to -1, meaning no way to tell.  */
 483
 484 /* We can't tell how many args there are
 485    now that the C compiler delays popping them.  */
 486
 487 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 488
 489 /* Return number of bytes at start of arglist that are not really args.  */
 490
 491 #define FRAME_ARGS_SKIP 8       /* Not sure on this. FIXMEmgo */
 492
 493 /* Put here the code to store, into a struct frame_saved_regs,
 494    the addresses of the saved registers of frame described by FRAME_INFO.
 495    This includes special registers such as pc and fp saved in special
 496    ways in the stack frame.  sp is even more special:
 497    the address we return for it IS the sp for the next frame.  */
 498 /* In the following implementation for RS6000, we did *not* save sp. I am
 499    not sure if it will be needed. The following macro takes care of gpr's
 500    and fpr's only. */
 501
 502 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS)             \
 503 {                                                                       \
 504   int ii, frame_addr, func_start;                                       \
 505   struct aix_framedata fdata;                                                   \
 506                                                                                 \
 507   /* find the start of the function and collect info about its frame. */        \
 508                                                                                 \
 509   func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET;\
 510   function_frame_info (func_start, &fdata);                                     \
 511   bzero (&(FRAME_SAVED_REGS), sizeof (FRAME_SAVED_REGS));                       \
 512                                                                                 \
 513   /* if there were any saved registers, figure out parent's stack pointer. */   \
 514   frame_addr = 0;                                                               \
 515   /* the following is true only if the frame doesn't have a call to alloca(),   \
 516       FIXME. */                                                                 \
 517   if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) {                           \
 518     if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame)                        \
 519       frame_addr = (FRAME_INFO)->prev->frame;                                   \
 520     else                                                                        \
 521       frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4);                \
 522   }                                                                             \
 523                                                                                 \
 524   /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's   \
 525      from saved_fpr to fp31 are saved right underneath caller stack pointer,    \
 526      starting from fp31 first. */                                               \
 527                                                                                 \
 528   if (fdata.saved_fpr >= 0) {                                                   \
 529     for (ii=31; ii >= fdata.saved_fpr; --ii)                                    \
 530       (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
 531     frame_addr -= (32 - fdata.saved_fpr) * 8;                                   \
 532   }                                                                             \
 533                                                                                 \
 534   /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's   \
 535      from saved_gpr to gpr31 are saved right under saved fprs, starting         \
 536      from r31 first. */                                                         \
 537                                                                                 \
 538   if (fdata.saved_gpr >= 0)                                                     \
 539     for (ii=31; ii >= fdata.saved_gpr; --ii)                                    \
 540       (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4);              \
 541 }
 542
 543 \f
 544 /* Things needed for making the inferior call functions.  */
 545
 546 /* Push an empty stack frame, to record the current PC, etc.  */
 547 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
 548
 549 #define PUSH_DUMMY_FRAME        push_dummy_frame ()
 550
 551 /* Discard from the stack the innermost frame,
 552    restoring all saved registers.  */
 553
 554 #define POP_FRAME       pop_frame ()
 555
 556 /* This sequence of words is the instructions:
 557
 558         mflr    r0              // 0x7c0802a6
 559                                 // save fpr's
 560         stfd    r?, num(r1)     // 0xd8010000 there should be 32 of this??
 561                                 // save gpr's
 562         stm     r0, num(r1)     // 0xbc010000
 563         stu     r1, num(r1)     // 0x94210000
 564
 565         // the function we want to branch might be in a different load
 566         // segment. reset the toc register. Note that the actual toc address
 567         // will be fix by fix_call_dummy () along with function address.
 568
 569         st      r2, 0x14(r1)    // 0x90410014 save toc register
 570         liu     r2, 0x1234      // 0x3c401234 reset a new toc value 0x12345678
 571         oril    r2, r2,0x5678   // 0x60425678
 572
 573                                 // load absolute address 0x12345678 to r0
 574         liu     r0, 0x1234      // 0x3c001234
 575         oril    r0, r0,0x5678   // 0x60005678
 576         mtctr   r0              // 0x7c0903a6 ctr <- r0
 577         bctrl                   // 0x4e800421 jump subroutine 0x12345678 (%ctr)
 578         cror    0xf, 0xf, 0xf   // 0x4def7b82
 579         brpt                    // 0x7d821008, breakpoint
 580         cror    0xf, 0xf, 0xf   // 0x4def7b82 (for 8 byte alignment)
 581
 582
 583   We actually start executing by saving the toc register first, since the pushing
 584   of the registers is done by PUSH_DUMMY_FRAME.  If this were real code,
 585   the arguments for the function called by the `bctrl' would be pushed
 586   between the `stu' and the `bctrl', and we could allow it to execute through.
 587   But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
 588   and we cannot allow to push the registers again.
 589 */
 590
 591 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
 592                     0x90410014, 0x3c401234, 0x60425678,             \
 593                     0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
 594                     0x4def7b82, 0x7d821008, 0x4def7b82 }
 595
 596
 597 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
 598 #define CALL_DUMMY_LENGTH 56
 599
 600 #define CALL_DUMMY_START_OFFSET 16
 601
 602 /* Insert the specified number of args and function address
 603    into a call sequence of the above form stored at DUMMYNAME.  */
 604
 605 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
 606         fix_call_dummy(dummyname, pc, fun, nargs, type)
 607
 608
 609 /* Signal handler for SIGWINCH `window size changed'. */
 610
 611 #define SIGWINCH_HANDLER  aix_resizewindow
 612 extern  void    aix_resizewindow ();
 613
 614 /* `lines_per_page' and `chars_per_line' are local to utils.c. Rectify this. */
 615
 616 #define SIGWINCH_HANDLER_BODY   \
 617                                                                         \
 618 /* Respond to SIGWINCH `window size changed' signal, and reset GDB's    \
 619    window settings approproatelt. */                                    \
 620                                                                         \
 621 void                                            \
 622 aix_resizewindow ()                             \
 623 {                                               \
 624   int fd = fileno (stdout);                     \
 625   if (isatty (fd)) {                            \
 626     int val;                                    \
 627                                                 \
 628     val = atoi (termdef (fd, 'l'));             \
 629     if (val > 0)                                \
 630       lines_per_page = val;                     \
 631     val = atoi (termdef (fd, 'c'));             \
 632     if (val > 0)                                \
 633       chars_per_line = val;                     \
 634   }                                             \
 635 }
 636
 637
 638 /* Flag for machine-specific stuff in shared files.  FIXME */
 639 #define IBM6000_TARGET